Summary: | 碩士 === 國立交通大學 === 應用化學系所 === 94 === Quantum dots and magnetic particles based analytical technology were developed in this dissertation. Water soluble CdSe quantum dots (QDs) were employed as the sensing probes for metal ions. The results demonstrated that the presence of gold, silver, copper, and mercury ions in sample solutions can quench the fluorescence of CdSe QDs, while the presence of cadmium ions are capable of enhancing the fluorescence of CdSe QDs. To differentiate mercury from copper ions, titania immobilized magnetic particles were employed to catalyze photo-reduction of the metal ions in sample solutions prior to CdSe QDs sensing. On the basis of the fluorescence changes of the sample mixed with CdSe QDs, before and after photo-reduction by titania beads, the metal ions can be roughly predicated using this approach.
The second part of the dissertation demonstrated a new preparation method for generating CdSe/ZnS core/shell QDs immobilized Fe3O4 magnetic particles. Organic CdSe/ZnS core/shell QDs were trapped to the surfaces of magnetic particles in aqueous solution via thiol-zinc binding. The generated fluorescence magnetic particles have been modified with a strand of DNA, which was capable of probing its complementary DNA. Additionally, the newly generated fluorescent particles can be used to sense the presence of dopamine in sample solutions on the basis of the observation of the quenching of fluorescence.
The final part of this dissertation presented a new matrix for surface-assisted laser desorption/ionization (SALDI) mass spectrometry. Carboxylic acid containing polymers immobilized magnetic particles were successfully demonstrated as the SALDI matrix without the need of the addition of proton source in the SALDI samples.
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